Security readout for executives and security teams
Plain-English summary
Adobe Lightroom Classic 10.3 and earlier had a flaw in the offline installer that could let an authenticated attacker gain higher privileges. The issue requires user interaction before installation, so this is not a remote drive-by risk, but it matters where old installers are retained or reused.
Executive priority
Treat this as a controlled remediation item, not an emergency. Prioritize cleanup if Adobe installers are centrally distributed, reused by IT, or stored on shared locations where local authenticated users could influence installation workflows.
Technical view
CVE-2021-40776 is a DLL hijacking privilege escalation issue tied to the Offline Lightroom Classic installer. The CVSS 3.1 score is 6.1 with physical attack vector, high privileges, low complexity, and required user interaction. Adobe links it to CWE-379.
Likely exposure
Exposure is most likely on endpoints or software repositories that still use or store Adobe Lightroom Classic 10.3 or earlier offline installers. Current exposure cannot be inferred from installation alone without confirming installer version and deployment source.
Exploitation context
The provided sources do not report active exploitation, and the CVE is not listed as KEV. Abuse requires an authenticated attacker and user interaction before product installation, which reduces broad internet-scale risk but leaves risk in local or shared installer workflows.
Researcher notes
Evidence is limited to the CVE record and Adobe advisory reference. Do not assume remote exploitability, active exploitation, or affected products beyond Lightroom Classic 10.3 and earlier offline installers. Validation should focus on installer provenance and retained deployment artifacts.
Mitigation direction
- Review Adobe APSB21-97 and follow the vendor’s update guidance.
- Replace Lightroom Classic 10.3 or earlier offline installers with vendor-approved current packages.
- Remove legacy offline installers from shared software repositories and endpoint caches.
- Restrict installer execution to trusted administrative deployment workflows.
- Prioritize systems where old installers are still used operationally.
Validation and detection
- Inventory Lightroom Classic offline installer packages and identify versions 10.3 or earlier.
- Confirm deployment tooling no longer references affected offline installers.
- Check software repositories, endpoint caches, and admin shares for retained legacy installers.
- Verify remediation against Adobe APSB21-97, not third-party fix claims.
- Record whether affected installers were ever used in privileged deployment contexts.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-379: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-40776 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H0.25.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://helpx.adobe.com/security/products/lightroom/apsb21-97.htmlCVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Creation of Temporary File in Directory with Insecure Permissions
Creation of Temporary File in Directory with Insecure Permissions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.